Tire(Tyre) Pressure

[dilan_randika]

Hi all,

Tyre Size: 195/65/R15

1. Printed recommended pressure on a such Tire may be 32-24.

But in SL, we never fill to this amount. So does it depend on the country or the road condition or on what?

2. What is the ideal Tire pressure for the above configuration being a 4 door sedan.

3. What are the results of non ideal tire pressure apart from bad for suspension & unwanted tire wear?

Thanks....

[Rumesh88]

1. The figures marked on a tyre are maximum load and pressure figures not the recommended figures.

2. The optimum tyre pressure depends on the vehicle load and hence may differ from vehicle to vehicle. Hence you should go with the vehicle manufacturer's recommendation. Ideally you should adjust the tyre pressure according to the load at a given time but it is not practical.

3. Apart from the given consequences, when a tyre is under inflated, the side wall may sustain damage (particularly so with radials) , give less fuel mileage, and when over inflated there will be less traction on the road and an uncomfortable ride but better on fuel.

Edited January 7, 2014 by Rumesh88

[Charith H Jayasinghe]

1. Can that be 32-24? It cannot be that much low. For a GT tyre 175*70*14 it's 44psi for inflation on first time

2. Agree. Go for the tire placard (most of the time it can be found near driver side where door comes and fixed) . If it is in kPa divide that value from 6.89.

3. There're also some safety issues http://www.tiresafety.com/ , http://www.michelin.co.uk/tyres/learn-share/care-guide/tyre-pressures

[CJ5]

The manufacturer recommended tyre pressure for the vehicle is usually found in the owner's manual and on the B pillar on the driver's side or on the driver's door frame .

I know of an SUV which has 265/70/15 tyres and the recommended pressure is 26psi ( 1.7bar / 179 KPa). The manufacturer recommended pressure for a particular car which I know of having 205/65/15 tyres is 31psi ( 2.2 bar / 220KPa).

Many people have said that 26 is way too low and not enough for that size of vehicle and 265/70/15 tyre and that 35-40 is the ideal.(pundits knowing more than the manufacturer!!) This I feel is because these "experts" have no idea what "psi" is and they feel it's the total weight of air inside the tyre.

The rear tyres of a Massey Furguson 240 tractor measuring 13.6x28, takes in only 10psi!!! While the tyres measuring 54x21.0-23 of an Airbus A330 requires a pressure of 200psi!!!

The psi (pounds per square inch) is not the weight of all the air inside a tyre rather the pressure within one square inch inside the tyre.

Contrary to popular belief, tyre pressure is not determined by the type of tyre or its size but upon the vehicle's load and driving application i.e. speed which many have absolutely no idea of.

Please correct me experts if I am wrong.

Edited January 8, 2014 by CJ5

[charithtg]

The manufacturer recommended tyre pressure for the vehicle is usually found in the owner's manual and on the B pillar on the driver's side or on the driver's door frame .

I know of an SUV which has 265/70/15 tyres and the recommended pressure is 26psi ( 1.7bar / 179 KPa). The manufacturer recommended pressure for a particular car which I know of having 205/65/15 tyres is 31psi ( 2.2 bar / 220KPa).

Many people have said that 26 is way too low and not enough for that size of vehicle and 265/70/15 tyre and that 35-40 is the ideal.(pundits knowing more than the manufacturer!!) This I feel is because these "experts" have no idea what "psi" is and they feel it's the total weight of air inside the tyre.

The rear tyres of a Massey Furguson 240 tractor measuring 13.6x28, takes in only 10psi!!! While the tyres measuring 54x21.0-23 of an Airbus A330 requires a pressure of 200psi!!!

The psi (pounds per square inch) is not the weight of all the air inside a tyre rather the pressure within one square inch inside the tyre.

Contrary to popular belief, tyre pressure is not determined by the type of tyre or its size but upon the vehicle's load and driving application i.e. speed which many have absolutely no idea of.

Please correct me experts if I am wrong.

Spot on...